In this paper we present three studies that investigate the individual differences in nonverbal listening behavior. Besides collecting a corpus of listener responses, we asked people to watch a video of a speaker and indicate where they would produce a listener response. Also we asked people to judge the appropriateness of listener responses that we generated using a virtual human. The combination of the multiple perspectives collected in these studies provides us with a rich data set in which different types of response opportunities are distinguishable. There are moments where there is high agreement between these multiple perspectives that a listener response is appropriate or inappropriate, moments where a listener response is controversial and moments neither a response was given nor a response was judged inappropriate (neutral). We will show that different contextual characteristics can be used to discriminate these response opportunities. Observations show relations to sentence structure, conversational structure and proximity of earlier responses.